Static [18F]FAZA images in BALB/c nude mice bearing two Caki-1 tumors on each upper flank. Image data are presented as maximum intensity projection (MIP) at 3 h post injection. Top left: control mouse versus sunitinib-treated mouse (9 days 40 mg/kg). Top right: control mouse versus a sunitinib-treated mouse which had received 13 days of drug therapy followed by 12 days after therapy was finished. Bottom: semi-quantified PET data as SUV in comparison to percent pimonidazole binding in tumor slices. Data as mean ± SEM from n analyzed tumors grown in x mice. *p < 0.05.